EP 0568474 A1 19931103 - MOS circuit for separating a synchronising signal in a composite video signal.
Title (en)
MOS circuit for separating a synchronising signal in a composite video signal.
Title (de)
MOS-Schaltung zum Extrahieren eines Synchronisierungssignals in einem BAS-Videosignal.
Title (fr)
Circuit d'extraction de signal de synchronisation dans un signal vidéo composite, en technologie MOS.
Publication
Application
Priority
FR 9205753 A 19920430
Abstract (en)
The invention relates to a circuit for separating the synchronisation signal from a composite video signal. The circuit includes a stage for aligning the synchronisation pulse background level with the earth potential (Vss), a stage for detecting the signal blanking level (Vsup) and a comparator (AD6) for comparing the aligned video signal (Sv') with a value intermediate between the synch background level and the blanking level. The detection circuit comprises a second comparator (AD5) charging or discharging a capacitor (C4) depending on the sign of the voltage between its inputs. The ratio Ic/Id between the values of charging current and discharging current is chosen (around 8) to obtain the correct Vsup value on the second input of the comparator (AD5). <IMAGE>
IPC 1-7
IPC 8 full level
H04N 5/08 (2006.01)
CPC (source: EP US)
H04N 5/08 (2013.01 - EP US)
Citation (search report)
- [A] US 4385319 A 19830524 - HASEGAWA KENICHI [JP]
- [A] EP 0200611 A2 19861105 - BENSON INC [US]
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0568474 A1 19931103; EP 0568474 B1 19971126; DE 69315371 D1 19980108; DE 69315371 T2 19980319; FR 2690804 A1 19931105; FR 2690804 B1 19940722; JP 3375172 B2 20030210; JP H0654224 A 19940225; US 5502500 A 19960326
DOCDB simple family (application)
EP 93420178 A 19930428; DE 69315371 T 19930428; FR 9205753 A 19920430; JP 9753593 A 19930423; US 5459293 A 19930429